A 19-3 would have been smack in the middle of the Punta years.
Bangor Punta owned S&W from 1965 until 1984.
QC during those years wasn't as good as it should have been & a whole lot of stuff was made that's borderline - such as the "just barely squeaks by being in spec" cylinder gap on your 19.
The drop in QC during those years was a fact.
The actual drop in QC wasn't all that bad.....it was greatly exaggerated.
It did used to have an effect on the value though.
That's one of the reasons I sought out M19's made during that period - they were excellent values.
And more importantly - all the ones I picked up were exceptionally good shooters.
Honestly though - if everything else works as it should then the CG isn't anything to worry about.
If it bothers you all that much, find someone with a chrono and clock some loads through it and see what it shows.